1. Field of the Invention
The invention relates in general to client-server computer systems, and more particularly, to reducing the connection time between clients and servers in a client-server computer system.
2. Description of Related Art
Computers are increasingly being used in the client-server configuration. In a client-server configuration, multiple computers are interconnected by a communication network. Certain computers are clients and other computers are servers. A client generates process requests, which are communicated to a server for processing. That is, a client generates requests and a server processes client requests. A particular computer can at times be a client and at other times a server.
One application of the client-server architecture is online transaction processing. Airline reservation and banking systems are classic examples of online transaction processing.
A principal advantage of the client-server architecture is the sharing of resources. Data, application programs, data storage devices, processing power, printers, communication subsystems, etc. can be shared. The client-server architecture also makes it possible to keep a centralized database, which is shared, as opposed to maintaining multiple copies of the same data with the overhead of insuring that the data remains consistent at all locations.
With continuing improvements in computer and communications technologies, the client-server architecture is being increasingly utilized. Computers can now be interconnected with local area networks and wide area networks, including wired telephone lines, cellular systems, satellite communication links, etc. The increased speed of communication networks that has been achieved have expanded the practical applications of client-server systems.
Furthermore, improvements in distributed servers, in which multiple computers act as servers that individually or together process client requests, have increased the applicability of the client-server architecture. For example, a distributed transaction processing system is possible. Furthermore, recent development of industry standards and client-server management software have made open distributed systems possible. In an open system, various types of computers running under various operating systems can be interconnected to form a distributed client-server system. This makes it possible for a client to have at its disposal a wide variety of computer resources. For example, TOP END.RTM., available from AT&T Global Information Solutions Company, is a client-server management system that makes open distributed transaction processing possible.
One significant cost associated with the client-server architecture is the cost of maintaining the connection between clients and servers. In client-server systems, when a client generates a request, the request is transmitted to a server via a communication network that interconnects the client and server computers. The client remains connected to the server via the communication network while the server processes the request. When the server completes processing the request, the server transmits a response message to the client. By maintaining an online connection between the client and the server, the client receives the response message as soon as the processing of its request is complete.
The costs associated with the online connection include communication network time (e.g., satellite, telephone line, and/or cellular communication links) and processor and memory overhead associated with the connection. Furthermore, as more clients are simultaneously connected to a server system, the bandwidth of the communication network must be increased to accommodate the many clients.
In some applications the client does not need a prompt result for its request. Furthermore, in some applications a client request takes a long time to process. In such and other applications the online connection time cost may be unnecessary overhead.
It can be seen then that there is a need for reducing the client-server connection costs while still providing the advantages of the client-server architecture.